Improving the performance of bulk packaging of liquids through the use of modified ethylene vinyl alcohol (EVOH) Edgard Chow (Technical Manager)

Robert Armstrong (TS&D Director) Kuraray America Inc.

Pasadena, TX SPE Polyolefins Conference Houston TX February 2012

Agenda

•

EVAL™ EVOH

– Typical applications – Properties •

Liquid packaging formats

– Bag-in-box – Intermediate bulk containers – Flexitants •

Improving the properties of EVOH

– Conventional EVOH – Amorphous EVOH – Elastomer modified EVOH

What is EVOH?

Ethylene mol % More flexible More orientable 24 27 32 35 38 44 48 Higher density Higher melt point Higher barrier a semi-crystalline thermoplastic and a random copolymer of E thylene and V inyl AL cohol (CH 2 -CH 2 ) m (CH 2 -CH) n OH

EVOH Protects Food

(Outside of packaging) Oxygen, off-odors, off-flavors, other contaminants Flavor, aroma, vitamins, modified atmosphere gases (Inside of packaging)

Versatility of EVOH

     

Oxygen barrier Aroma barrier Vitamin protection Flavor preservation Solvent barrier Hydrocarbon barrier Oxygen Toluene Xylene Mint Vitamin C Coffee

Agenda

•

EVAL™ EVOH

– Typical applications – Properties •

Liquid packaging formats

– Bag-in-box – Intermediate bulk containers – Flexitants •

Improving the properties of EVOH

– Conventional EVOH – Amorphous EVOH – Elastomer modified EVOH

The Iconic BIB Application

• Advantage over glass – More functional • Single cup dispensing convenience • No headspace • Can stay open up to 21 days – More sustainable* • 85% less packaging/landfill waste • 53% less CO2 emissions Source: www.betterwinesbetterworld.com/

Wine BIB Requirements

• High barrier – 0.5 ~ 0.8 cc/m 2 .day.atm @ 20 °C, 65%RH – EVAL™ L171B = 27mol% Et. EVOH • • • High abuse resistance

Transportation Abuse

Up/down motion in land Side/side motion in sea

Potential Outcome

• • Pinhole formation OTR deterioration

Standard Test Method

• • ASTM F193-92 ASTM D3985 • • •

Adopted Wine Industry Specifications 0 pinholes max. after 200 gelbo flex cycles 2 pinholes max. after 400 gelbo flex cycles OTR < 1.0 cc/m2.day.atm

Evaluation Method

ASTM F193-92 Reapproved 2004 45 CPM, full flex condition ASTM D3985 20 °C, 65%RH

Gelbo flex testing Oxygen transmission rate

Evaluation of Market Samples PE inner liner Barrier outer liner



Inner layer : PE 40



Outer layer :



OTR : 1.0

(in) PE 30 // VM-PET 12 //EVA 40 (out) cc/m 2 /day/atm , 2.8

cc/m 2 /day/atm



WVTR : 5.7

g/m 2 /day



Inner layer : PE 90



Outer layer :



OTR : 0.8

(in) PE 40 /Tie/ EVOH 6 /Tie/PE 60 (out) cc/m 2 /day/atm



WVTR : 2.6

g/m 2 /day



Inner layer : PE 40



Outer layer :



(in) EVA 15 /Tie/ EVOH 6 /Tie/EVA 7 //ON 10 //PE 30 (out) OTR : 0.6

cc/m 2 /day/atm



WVTR : 5.9

g/m 2 /day

Test conditions: OTR:20ºC/65%RH, WVTR:40ºC/90%RH

Evaluation of Market Samples

Oxygen Transmission Rate After Gelbo Flex

Olive Oil BIB Applications (3 – 20L) Cola Syrup Juice concentrate Coffee concentrate Drums (200L) IBC(1000 – 1500 L) Aran Packaging Bluesept55 ® Sealed Air Cryovac Entapack ®

Flexitank Market

• Typically in the 12,000 to 36,000L range • Must comply with the

Code of Standards

by the

Container Owners Association

• The flexitank market size is

~500,000

units • Recent 7-layer installation by

Raven Industries

Flexitank Benefit

• 20 ft Container payload – 15% higher than IBCs – 44% higher than drums Source: www.unedecom.com

Flexitank Market

• EPT Wine-Pac™ has a third inner liner of

EVOH

film • OTR of

0.4 cc/m 2 .day

• Applications – Food & beverage: wine, oils, juice concentrates, etc.

– Cosmetics: detergents, bleaching solutions, cleaners, etc.

– Industrial chemicals: adhesives, paints, biofuels, fuel additives, etc.

Source: http://eptpac.com

Trends with big bags

• The larger the bag, … – the lower the barrier requirements • Surface area to volume ratio factor – but the higher the physical abuse on the bag • Normal stresses induced by higher loads • Use of multiple liners similar to BIB is also practiced

3 – 5L retail BIB 3 – 20L institutional BIB 200 – 1500L IBC 12000 – 36000L Flexitank

High Barrier Flexitank Challenges

• Limited experience base producing large, thick bags with thin EVOH layers – Larger dies, longer residence time in the melt demand improved thermal stability • Use of higher ethylene grades • Selection of EVAL 7-series – Longer time for the bubble to reach its finished geometry • Higher ethylene grades have a lower recrystallization temperature – Higher flex crack resistance • Use of softer modified grades

Agenda

•

EVAL™ EVOH

– Typical applications – Properties •

Liquid packaging formats

– Bag-in-box – Intermediate bulk containers – Flexitants •

Improving the properties of EVOH

– Conventional EVOH – Amorphous EVOH – Elastomer modified EVOH

Failure Mechanism of Pinhole Formation

Fatigue Cracking From radical generation on to micro-crack generation

Inhibition of crack growth is critical to improve flexible crack resistance

Type

EVAL

EVAL Technologies for Liquid Packaging

Technology Illustration Flex crack resistance

Conventional Good EVAL SP Amorphous EVOH Better EVAL FS Elastomer modified EVOH Domain-matrix Best

Film Pilot Equipment

•

Blown film production Brampton Engineering 7 layer, 6” pancake die Materials

– Sclair FP120 C8-LLDPE – Ultrathene UE624000 18% vinyl acetate EVA – Admer NF498A LLDPE-based tie resin – Dupont Byner 3861 EVA-based tie resin – Various types of EVAL •

Cast film production Toyo-seiki 20mm metering screw 300mm coat hanger die Gelbo flex conditions

– 45 CPM, full flex, room temperature

Effect of EVOH Grade and Thickness

Number of gelbo cycles to create one (1) pinhole

Coex blown film structure: LLDPE/Tie/

EVAL

/Tie/LLDPE = 36 / 5 /

X

/ 5 / 36 μm 1200

1000 1000

1000

900 900 800

800

700

600

400

400

300 300

200 0

30

20μm 4μm Mono 6μm 15μm 20μm 20μm 4μm Coex Mono F171 6μm 15μm 20μm Coex FS101

Effect of Structure Stiffness

Number of gelbo cycles to create one (1) pinhole

• Film structure – 20μm monolayer cast film – 90μm blown film: LLDPE/LL-Tie/

EVAL

/LL-Tie/LLDPE = 36/5/

8

/5/36 μm – 90μm blown film: LL+EVA/EVA-Tie /

EVAL

/EVA-Tie/LL+EVA = 36/5/

8

/5/36 μm

Flex Crack Resistance of EVAL FS101

Number of gelbo cycles to create one (1) pinhole

• Structure: 90 μm blown film: LLDPE/LL-Tie/

EVAL

/LL-Tie/LLDPE = 36/5/

8

/5/36 6 4 2 0 16 14 12 10 8

0

1 500

0 3,8

3,2

1

1000

Number of Gelbo Cycles 14

9 2000

4,6

F171(32) J171(32) FS101(32)

More developments underway

Number of gelbo cycles to create one (1) pinhole

• Structure: 20μm monolayer cast film

Type

EVAL

EVAL Grades for Liquid Packaging

Technology

Conventional

Flex crack resistance

Good

Grades (et.mol%)

EVAL SP Amorphous EVOH Better L171(27) F171(32) H171(38) E171(44) SP521(27) J171(32) XEP-1035(38) EVAL FS Elastomer modified EVOH Best FS101(32) XEP-1273(32)

Summary

• EVOH has excellent barrier properties • EVOH has great flex crack resistance when coextruded with softer polyolefin resins • The use of EVOH in BIB is established but grades with improved the flex crack resistance for larger bags such as flexitanks have been developed • We can sample any of the mentioned grades upon your request

Thank You!

Presented by: Edgard Chow phone (281) 474-1558 [email protected]

Acknowledgement Mr. Wataru Hirose (EVAL R&D Japan)